Cooling system controller for internal combustion engines

Abstract

A cooling systems controller for internal combustion engines having two circuits of cooling water for cylinder head side and cylinder block side, each of two circuits being provided with a radiator, a water jacket, a water pump, a conduit, a return passageway, a bypass passageway, a mixing valve, and a motor fan; two heater circuits being provided so as to branch from and return to said main two cooling water circuits, said heater circuits being provided with a first selector valve to junction them and a second selector valve to separate them, said selector valve having a function to supply the higher temperature water from either of two water circuits to a heater radiator by the signals from a control unit for judging which temperature of two circuits is higher, thereby making it possible to obtain more rapid heating effect at the time immediately after starting up the engine without reducing the heating efficiency during normal runs of vehicle.

What is claimed is: 
     
       1. A cooling system controller for internal combustion engines comprising: a first radiator and a second radiator,   a first water jacket provided to a cylinder head,   a second water jacket provided to a cylinder block,   a first water pump and a second water pump, being provided respectively at the upperstream side of said first or second water jacket,   a first and second conduits, connecting respectively an outlet port at the downstream side of said first or second water jacket to an inlet port of said first or second radiator,   a first return passageway and a second return passageway, connecting respectively an outlet port of said first or second radiator to said first or second water pump,   a first bypass passageway and a second bypass passageway, being branched respectively from said first or second conduit and communicating respectively with said first or second return passageway,   a first mixing valve and a second mixing valve, being disposed respectively at the junction of said first or second bypass passageway and said first or second return passageway, to mix cooling water of the two passageways and return it to said first or second water pump respectively,   a first motor fan and a second motor fan, to supply cooling water respectively to said first or second radiator,   a first heater circuit and second heater circuit, being branched out respectively at the outlet port of the downstream side of said first or second water jacket,   said first and second heater circuits being junctioned by a first selector valve at the upperstream of a heater radiator, being separated by a second selector valve at the downstream of said heater radiator, and returning respectively to a main water circuit at a position which is on the upperstream of said first or second water pump and on the downstream of said first or second mixing valve, and   said first and second selector valves having the function to supply water of the higher temperature from either of said first and second water jackets to said heater radiator by the signals from a control unit which detects the temperature at the downstream side outlet ports of said first and second water jackets and compares them, and having the function to shut off both water flows.